diff --git a/lib/graph3d/Graph3d.js b/lib/graph3d/Graph3d.js
index aae7e869..f84908ef 100644
--- a/lib/graph3d/Graph3d.js
+++ b/lib/graph3d/Graph3d.js
@@ -846,6 +846,12 @@ Graph3d.prototype.getPointDrawingMethod = function() {
     case Graph3d.STYLE.DOTSIZE:
       pointDrawingMethod = Graph3d.prototype._redrawDotSizeGraphPoint;
       break;
+    case Graph3d.STYLE.SURFACE:
+      pointDrawingMethod = Graph3d.prototype._redrawSurfaceGraphPoint;
+      break;
+    case Graph3d.STYLE.GRID:
+      pointDrawingMethod = Graph3d.prototype._redrawGridGraphPoint;
+      break;
   }
 
   return pointDrawingMethod;
@@ -875,11 +881,7 @@ Graph3d.prototype.redraw = function() {
   } else {
     // Use the old style drawing methods
 
-    if (this.style === Graph3d.STYLE.GRID ||
-      this.style === Graph3d.STYLE.SURFACE) {
-      this._redrawDataGrid();
-    }
-    else if (this.style === Graph3d.STYLE.LINE) {
+    if (this.style === Graph3d.STYLE.LINE) {
       this._redrawDataLine();
     }
     else {
@@ -1414,108 +1416,6 @@ Graph3d.prototype._hsv2rgb = function(H, S, V) {
 };
 
 
-Graph3d.prototype._drawGridLine = function(ctx, from, to) {
-  if (from === undefined || to === undefined) {
-     return;
-  }
-
-  // calculate Hue from the current value. At zMin the hue is 240, at zMax the hue is 0
-  var zAvg = (from.point.z + to.point.z) / 2;
-  var h    = (1 - (zAvg - this.zMin) * this.scale.z  / this.verticalRatio) * 240;
-
-  ctx.lineWidth   = this._getStrokeWidth(from) * 2;
-  ctx.strokeStyle = this._hsv2rgb(h, 1, 1);
-  this._line(ctx, from.screen, to.screen);
-};
-
-
-/**
- * Draw all datapoints as a grid
- * This function can be used when the style is 'grid'
- */
-Graph3d.prototype._redrawDataGrid = function() {
-  var ctx = this._getContext(),
-    point, right, top, cross,
-    i,
-    topSideVisible, fillStyle, strokeStyle, lineWidth,
-    h, s, v, zAvg;
-
-  if (this.dataPoints === undefined || this.dataPoints.length <= 0)
-    return; // TODO: throw exception?
-
-  this._calcTranslations(this.dataPoints);
-
-  if (this.style === Graph3d.STYLE.SURFACE) {
-    for (i = 0; i < this.dataPoints.length; i++) {
-      point = this.dataPoints[i];
-      right = point.pointRight;
-      top   = point.pointTop;
-      cross = point.pointCross;
-
-      if (point !== undefined && right !== undefined && top !== undefined && cross !== undefined) {
-
-        if (this.showGrayBottom || this.showShadow) {
-          // calculate the cross product of the two vectors from center
-          // to left and right, in order to know whether we are looking at the
-          // bottom or at the top side. We can also use the cross product
-          // for calculating light intensity
-          var aDiff = Point3d.subtract(cross.trans, point.trans);
-          var bDiff = Point3d.subtract(top.trans, right.trans);
-          var crossproduct = Point3d.crossProduct(aDiff, bDiff);
-          var len = crossproduct.length();
-          // FIXME: there is a bug with determining the surface side (shadow or colored)
-
-          topSideVisible = (crossproduct.z > 0);
-        }
-        else {
-          topSideVisible = true;
-        }
-
-        if (topSideVisible) {
-          // calculate Hue from the current value. At zMin the hue is 240, at zMax the hue is 0
-          zAvg = (point.point.z + right.point.z + top.point.z + cross.point.z) / 4;
-          h = (1 - (zAvg - this.zMin) * this.scale.z  / this.verticalRatio) * 240;
-          s = 1; // saturation
-
-          if (this.showShadow) {
-            v = Math.min(1 + (crossproduct.x / len) / 2, 1);  // value. TODO: scale
-            fillStyle = this._hsv2rgb(h, s, v);
-            strokeStyle = fillStyle;
-          }
-          else  {
-            v = 1;
-            fillStyle = this._hsv2rgb(h, s, v);
-            strokeStyle = this.axisColor; // TODO: should be customizable
-          }
-        }
-        else {
-          fillStyle = 'gray';
-          strokeStyle = this.axisColor;
-        }
-
-        ctx.lineWidth = this._getStrokeWidth(point);
-        ctx.fillStyle = fillStyle;
-        ctx.strokeStyle = strokeStyle;
-        ctx.beginPath();
-        ctx.moveTo(point.screen.x, point.screen.y);
-        ctx.lineTo(right.screen.x, right.screen.y);
-        ctx.lineTo(cross.screen.x, cross.screen.y);
-        ctx.lineTo(top.screen.x, top.screen.y);
-        ctx.closePath();
-        ctx.fill();
-        ctx.stroke(); // TODO: only draw stroke when strokeWidth > 0
-      }
-    }
-  }
-  else { // grid style
-    for (i = 0; i < this.dataPoints.length; i++) {
-      point = this.dataPoints[i];
-      this._drawGridLine(ctx, point, point.pointRight);
-      this._drawGridLine(ctx, point, point.pointTop);
-    }
-  }
-};
-
 Graph3d.prototype._getStrokeWidth = function(point) {
   if (point !== undefined) {
     if (this.showPerspective) {
@@ -1539,7 +1439,7 @@ Graph3d.prototype._getStrokeWidth = function(point) {
  * Draw a bar element in the view with the given properties.
  */
 Graph3d.prototype._redrawBar = function(ctx, point, xWidth, yWidth, color, borderColor) {
-  var i, j, surface, corners;
+  var i, j, surface;
 
   // calculate all corner points
   var me = this;
@@ -1605,16 +1505,40 @@ Graph3d.prototype._redrawBar = function(ctx, point, xWidth, yWidth, color, borde
   // NOTE: we start at j=2 instead of j=0 as we don't need to draw the two surfaces at the backside
   for (j = 2; j < surfaces.length; j++) {
     surface = surfaces[j];
-    corners = surface.corners;
-    ctx.beginPath();
-    ctx.moveTo(corners[3].screen.x, corners[3].screen.y);
-    ctx.lineTo(corners[0].screen.x, corners[0].screen.y);
-    ctx.lineTo(corners[1].screen.x, corners[1].screen.y);
-    ctx.lineTo(corners[2].screen.x, corners[2].screen.y);
-    ctx.lineTo(corners[3].screen.x, corners[3].screen.y);
-    ctx.fill();
-    ctx.stroke();
+    this._polygon(ctx, surface.corners);
+  }
+};
+
+
+/**
+ * Draw a polygon using the passed points and fill it with the passed style and stroke.
+ *
+ * @param points      an array of points. 
+ * @param fillStyle   optional; the fill style to set
+ * @param strokeStyle optional; the stroke style to set
+ */
+Graph3d.prototype._polygon = function(ctx, points, fillStyle, strokeStyle) {
+  if (points.length < 2) {
+    return;
+  }
+
+  if (fillStyle !== undefined) {
+    ctx.fillStyle   = fillStyle;
+  }
+  if (strokeStyle !== undefined) {
+    ctx.strokeStyle = strokeStyle;
+  }
+  ctx.beginPath();
+  ctx.moveTo(points[0].screen.x, points[0].screen.y);
+
+  for (var i = 1; i < points.length; ++i) {
+    var point = points[i];
+    ctx.lineTo(point.screen.x, point.screen.y);
   }
+
+  ctx.closePath();
+  ctx.fill();
+  ctx.stroke(); // TODO: only draw stroke when strokeWidth > 0
 };
 
 
@@ -1796,6 +1720,96 @@ Graph3d.prototype._redrawDotSizeGraphPoint = function(ctx, point) {
 };
 
 
+/**
+ * Draw single datapoint for graph style 'surface'.
+ */
+Graph3d.prototype._redrawSurfaceGraphPoint = function(ctx, point) {
+  var right = point.pointRight;
+  var top   = point.pointTop;
+  var cross = point.pointCross;
+
+  if (point === undefined || right === undefined || top === undefined || cross === undefined) {
+    return;
+  }
+
+  var topSideVisible = true;
+  var fillStyle;
+  var strokeStyle;
+  var lineWidth;
+
+  if (this.showGrayBottom || this.showShadow) {
+    // calculate the cross product of the two vectors from center
+    // to left and right, in order to know whether we are looking at the
+    // bottom or at the top side. We can also use the cross product
+    // for calculating light intensity
+    var aDiff = Point3d.subtract(cross.trans, point.trans);
+    var bDiff = Point3d.subtract(top.trans, right.trans);
+    var crossproduct = Point3d.crossProduct(aDiff, bDiff);
+    var len = crossproduct.length();
+    // FIXME: there is a bug with determining the surface side (shadow or colored)
+
+    topSideVisible = (crossproduct.z > 0);
+  }
+
+  if (topSideVisible) {
+
+    // calculate Hue from the current value. At zMin the hue is 240, at zMax the hue is 0
+    var zAvg = (point.point.z + right.point.z + top.point.z + cross.point.z) / 4;
+    var h    = (1 - (zAvg - this.zMin) * this.scale.z  / this.verticalRatio) * 240;
+    var s    = 1; // saturation
+    var v;
+
+    if (this.showShadow) {
+      v = Math.min(1 + (crossproduct.x / len) / 2, 1);  // value. TODO: scale
+      fillStyle = this._hsv2rgb(h, s, v);
+      strokeStyle = fillStyle;
+    }
+    else  {
+      v = 1;
+      fillStyle = this._hsv2rgb(h, s, v);
+      strokeStyle = this.axisColor; // TODO: should be customizable
+    }
+  }
+  else {
+    fillStyle = 'gray';
+    strokeStyle = this.axisColor;
+  }
+
+  ctx.lineWidth = this._getStrokeWidth(point);
+  // TODO: only draw stroke when strokeWidth > 0
+
+  var points = [point, right, cross, top];
+  this._polygon(ctx, points, fillStyle, strokeStyle);
+};
+
+
+/**
+ * Helper method for _redrawGridGraphPoint()
+ */
+Graph3d.prototype._drawGridLine = function(ctx, from, to) {
+  if (from === undefined || to === undefined) {
+     return;
+  }
+
+  // calculate Hue from the current value. At zMin the hue is 240, at zMax the hue is 0
+  var zAvg = (from.point.z + to.point.z) / 2;
+  var h    = (1 - (zAvg - this.zMin) * this.scale.z  / this.verticalRatio) * 240;
+
+  ctx.lineWidth   = this._getStrokeWidth(from) * 2;
+  ctx.strokeStyle = this._hsv2rgb(h, 1, 1);
+  this._line(ctx, from.screen, to.screen);
+};
+
+
+/**
+ * Draw single datapoint for graph style 'Grid'.
+ */
+Graph3d.prototype._redrawGridGraphPoint = function(ctx, point) {
+  this._drawGridLine(ctx, point, point.pointRight);
+  this._drawGridLine(ctx, point, point.pointTop);
+};
+
+
 /**
  * Draw all datapoints for currently selected graph style.
  *